Excitation functions for shell-stabilized evaporation residues produced in 48 Ca -induced reactions with 154 Gd , 159 Tb , 162 Dy , and 165 Ho targets have been measured in experiments performed at the Cyclotron Institute at Texas A&M University. The examined energy range predominantly covers the 3 n and 4 n evaporation channels with higher cross sections measured for the 4 n products. The σ 4 n are nearly invariant within experimental uncertainty in reactions with 159 Tb , 162 Dy , and 165 Ho with the maxima at 12.6 ± 1.9, 12.6 ± 1.7, and 9.4 ± 1.3more » mb, respectively. For the reaction with 154 Gd , the maximum is slightly lower at 4.0 ± 0.6 mb. A simple model to describe the measured production cross sections was employed. Capture was estimated by using the “diffused barrier formula” from the “fusion by diffusion” model proposed by Swiatecki et al. [Phys. Rev. C 71, 014602 (2005)]. The fusion probability was estimated by using a phenomenological expression presented by Siwek-Wilczynska et al. [Int. J. Mod. Phys. E 17, 12 (2008)]. The survival probability was calculated according to the formula of Vandenbosch and Huizenga [Nuclear Fission (Academic, New York, 1973)], derived from transition-state theory. The best agreement is reached between calculation and experiment upon inclusion of collective effects in the calculation of the survival probability, shown previously to be important for production of weakly deformed nuclei. This, in turn, challenges the expectation that strong shell stabilization benefits the production cross section. The present data are compared with earlier studies on production of neutron-deficient nuclei in Ca-induced reactions with lanthanide targets.« less

We have studied the C-14,C-15(d,He-3)B-13,B-14 proton-removing reactions in inverse kinematics. The (d,He-3) reaction probes the proton occupation of the target ground state, and also provides spectroscopic information about the final states in B-13,B-14. The experiments were performed using C-14,C-15 beams from the ATLAS accelerator at Argonne National Laboratory. The reaction products were analyzed with the HELIOS device. Angular distributions were obtained for transitions from both reactions. The C-14-beam data reveal transitions to excited states in B-13 that suggest configurations with protons outside the pi(0p(3/2)) orbital, and some possibility of proton cross-shell 0p-1s0d excitations, in the C-14 ground state. The C-15-beammore » data confirm the existence of a broad 2(-) excited state in B-14. The experimental data are compared to the results of shell-model calculations.« less